Technical Field
The present invention relates to wavelength division multiplexing and, in particular, to filtering specific wavelengths in polymer waveguides.
Description of the Related Art
One option for increasing the aggregate data transfer rate in an optical system is to use wavelength division multiplexing (WDM) to transmit multiple signal channels having different wavelengths in a single fiber core. This increases the channel density, allowing substantially more information to be sent using the same number of fibers cores.
Recent efforts have focused on integrating polymer waveguides with opto-electronic chip arrays (including, e.g., vertical cavity surface-emitting lasers (VCSELs) and photodiodes) to increase the bandwidth density of an optical transmission system. However, there are challenges in implementing WDM with polymer waveguides. Typically, micro-mirrors using a total internal reflection effect or a gold metal coating are used to couple light from the VCSELs into waveguide cores and from the waveguide cores to the photodiodes. However, such micro-mirrors have no wavelength selectivity in the relevant spectral range and cannot be used as filters with a light signal having multiple wavelengths. As such, conventional micro-mirrors are inadequate for use in implementing WDM with polymer waveguides.